Dialogflow Knowledge base data is not send in response for Twilio

I have completed the integration as per the documentation when i try to run the bot by asking the question which is provided in the knowledge base it doesn't send reply. Instead, it sends only the default fallback intent response.

If i revert back the normal i am getting the response properly.

Start by reproducing the Dialogflow-to-Twilio flow with a question from the knowledge base, then compare it with a normal question that returns correctly. Trace where the knowledge-base result becomes the Twilio response and where the default fallback intent is selected. Done means knowledge-base questions return their Dialogflow data through Twilio instead of only the fallback response.

Written by the indexing model from the issue text.